Devices for mixing gases with liquids



March 1955 J. H. MATHERS DEVICES FOR MIXING GASES WITH LIQUIDS Filed Aug. 24, 1955 Inventor (/O/l/V HERBERT N19 THERS United States Patent DEVICES FOR MIXING GASES WITH LIQUIDS John Herbert Mathers, Hamble, near Southampton, England Application August 24, 1953, Serial No. 376,157

Claims priority, application Great Britain August 25, 1952 1 Claim. (Cl. 261-) This invention relates to devices for mixing gases with liquids and more especially to silencers of the kind in which cooling liquid is mixed with the exhaust gases of an internal combustion engine and is thereafter discharged to waste, together with the gases, or is separated out from the exhaust gases for recirculation. Such silencers are commonly used, for example, on ships whereby cooling water may be drawn in from the sea, river or the like; before being mixed with the exhaust gases the cooling water may be passed through the usual coolant circuit of the engine.

In a known type of construction the device has a vertical pipe open at its upper end and fed from below with the gases, a cooling plate secured in spaced relationship over the open upper end of the pipe and having a depending flange arranged externally about and spaced from the pipe with its lower edge below the upper end of the pipe, and a casing surrounding and spaced from the cooling plate and pipe and having an inlet and an outlet for cooling liquid respectively above and below the cooling plate. In such a device the gases rise through the pipe, impinge against the cooling plate and are thereby simultaneously cooled and directed downwardly between the flange and pipe, mixed with the cooling liquid passing downwardly within the casing about the periphery of the cooling plate, and are led away through the outlet of the casing.

It is the main object of the present invention to provide an improved form of construction of device, of the type described above, wherein jet forming means are provided for direction of the cooling liquid into the exhaust gas stream passing downwardly about the pipe but wherein such jet forming means do not result in any noticeable restriction of the flow of the cooling liquid whereby such flow can be readily varied within much wider limits and a more efiective and adaptable silencer is obtained.

According to the present invention, in a device of this type inwardly projecting annular deflector means are disposed about the internal wall of the casing in the path of flow of cooling liquid as it passes between the casing and the flange or the pipe for directing part or all of the cooling liquid inwardly as a jet, or series of jets, away from the wall of the casing and into the gas stream for better mixing therewith. The dimensions are made such that the deflector means extend only partially across the liquid flow passage bounded externally by the easing so that the liquid flow remains substantially unrestricted.

The jet (or jets) has two important functions in relation to the exhaust gases, viz:

(l) The cooling liquid is directed in a jet or spray into the gases at a pressure which increases with increase of engine speed so as to reduce noise and maintain effective cooling, and

(2) The jet induces an efficient flow or extraction of gases which reduces back pressure in the exhaust passage prior to the silencer.

2,738,961 Patented Mar. 20, 1956 The deflector means are preferably so arranged as to direct all or part of the flow of cooling liquid against the pipe, and preferably along the major part of the length of the pipe, whereby very effective cooling of the pipe may be obtained.

The deflector means may take the form of an inwardly bulged portion of the Wall of the casing, e. g. by a reduction of the diameter of the casing.

The deflector means are advantageously arranged adjacent the lower rim of the depending flange and the rim is adjacent the upper end of the pipe so that the exhaust gases emerging from between the flange and the pipe are met substantially immediately by the jet or jets formed, and so that the greatest possible area of the pipe is submitted to the action of the cooling liquid.

The cooling plate may conveniently be seated on the pipe by suitable spacers so as to be readily removable through the top of the casing. The casing may have a top cover plate adapted to clamp the cooling plate on to the pipe so that removal of said top cover plate permits simple lifting out of the cooling plate.

A construction of the silencer is hereinafter particularly described by way of example with reference to the accompanying drawing which is a vertical central section.

In this drawing the pipe 1 has an inlet elbow 2 and is formed integrally with an external cylindrical casing 3. A cooling plate 4, having a depending flange 5, is seated (by spacing lugs 12 thereon) on the open upper end of the pipe 1. The upper end of the cylindrical casing 3 receives a cover plate 6 which is domed centrally and abuts against upper space distance lugs 7 on the cooling plate 4 to clamp the plate in position. The lugs 7 are spaced to permit flow of the liquid down over the periphcry of the cooling plate, the cover plate 5 being centrally apertured at 8, for the entry or" the cooling liquid. The diameter of the internal wall of the cylindrical casing 3 is reduced downwardly, from a point adjacent to the lower rim of the flange 5 to as to provide a shoulder or bulged portion 9 which serves to direct the stream of cooling liquid, passing down between the casing 3 and flange 5, inwardly into the stream of exhaust gases at an angle of between twenty and forty-five degrees to the vertical, and against the external wall of the pipe 1 along the greater part of the length of said pipe for effective cooling thereof. The mixture of cooling liquid and exhaust gases flows out of the casing through an outlet opening 10, and a drain 11 is provided at the base of the casing.

With such a construction an efficient cooling and mixing action is obtained which results in a very satisfactory suppression of noise. The exhaust gases are cooled and are turned into a downward path at the same position, viz. adjacent to the cooling plate, whereby back pressure is largely avoided.

As the inlet elbow of the pipe, providing a short horizontal inlet, is also located in the path of the cooling liquid the heat which would otherwise be dispersed into the engine room by a normal connecting elbow pipe is absorbed by the cooling liquid.

The casing, cooling plate and cover plate may conveniently be cast in an aluminium alloy.

The disposition of the upper end of the pipe above the lower rim of the flange ensures that the cooling liquid does not enter the pipe.

The silencer made in accordance with the invention not only provides an efficient suppression of noise but also enables a silencer of small dimensions to give highly satisfactory results.

In a constructional form of the invention designed for a horsepower marine engine the casing 3 is cast integrally with the elbow and pipe as shown, and has a height of 'about 1:1 :or l2 -inehes.

v The interior diameter of the pipe 1 is about two and a half inches and the interior diameter of the casing is about four and a half inches. The upper end ofthe casing is open and about aninch-above the upper end. of the .pipe.

7 A silencermadetin accordance with thisinvention may be incorporated as part of the exhaustmanifold of an engine of a motor car or rail vehicle upwardly about centrally between its ends and suitable means are provided for separating thegases .fromthe water andtrecirculation the water backto theainlet .8.

Although the invention-has been particularly described as applied to the silencing of internal combustion engines, it could likewise be utilised as.-a cooling meanslfor other hotggases,or.as a smoke washer or. dust trap.

Where the silencer is cast in an aluminium or other light alloy, a sleeve 13 ofstainless steel .or other'heat and erosion resistant material is conveniently fitted to the part of pipe 1 against which the water impinges, This sleeve maybe cast in position.

What I claim is:

.A device for mixing liquids with gases comprising a vertical pipeopen at its .upper end, rneans for feeding gases in at the lower end of said,pipe, a cooling plate secured in spaced relationship over theiupper'end of the pipe so that the gases impingeagainst one sideof said plate, 'a depending flange .on thetcooling plate arranged externally about and spaced from the pipe and having its lower edge only a short distance below the upper end of the pipe, a casing surrounding and spaced-from the other side of-and around the-cooling plate and around the pipe and defining therewith a passage for cooling liquid and gases so that the cooling liquid impinges against the other side of said cooling plate, said casing having an outlet for mixed cooling liquid and gases below the cooling plate, a top cover plate for the casing, distance lugs spaced apart from each otherand disposed between said top (cover plate and said coolingplate whereby the cover plate clamps the cooling'plate on to the pipe, 'the removal of the top @cover plate permitting simple lifting out of the cooling plate,-said top cover plate being centrally apertured for the inflow of cooling liquid on to the top surface ofthe coolingplatewhence said liquid flows between saidlugsand down over the periphery of the cooling plate, and annular deflector means disposed round the internal wall of the casing, and projecting inwardly from said wall, said deflector means being arranged in the path of flow of the cooling liquid through the casing so as todirect cooling liquid inwardly in jet 'form away from the surface of the casing and on to the major part of said pipe to mix with gases flowing downwardly-between the pipe and easing.

References Cited in the file of this patent UNITED STATES PATENTS 940,290 Tobey Nov. 16, 1909 1,089,259 Patten Mar. 3, 1914 1,606,032 Kolstrand Nov. 9, 1926 2,675,218 Bletcher et al. Apr. 13, 1954 

